WPF网格和DataGrid大小 [英] WPF Grid and DataGrid sizing

问题描述

UserControl 我正在努力工作基本上是这样布置的：

 < Grid> 
< Grid.RowDefinitions> 
< Row Height =*/> 
< Row Height =*/> 
< /Grid.RowDefinitions> 
< wpftoolkit：DataGrid x：Name =PrimaryGrid/> <！〜〜10行 - > 
< Border> 
< Grid> 
< Grid.RowDefinitions> 
< Row Height =*/> 
< Row Height =*/> 
< /Grid.RowDefinitions> 
< wpftoolkit：DataGrid x：Name =SecondaryGrid/> <！〜〜2行 - > 
< wpftoolkit：DataGrid x：Name =OtherGrid/> <！〜〜50行 - > 
< / Grid> 
< / Border> 
< / Grid> 
  

这个 UserControl 然后放在我的窗口作为 Grid 的最后一个成员，唯一一个 Height =*。我遇到了 DataGrid 的大小问题。

如果我将 UserControl 的 VerticalAlignment code> Stretch 在窗口中，然后 PrimaryGrid 获得1/2高度的 UserControl ，并且 Border 中的每一个都获得1/4。它们的大小如此，无论每个行的行数如何，留下 OtherGrid 具有太小的垂直空间，而其他在滚动视图中具有非行空格。

如果我将 VerticalAlignment 设置为顶部，网格似乎很漂亮对于他们的内容，除了在 UserControl 的底部留下一个莫名其妙的空白。我使用Snoop， RowDefinition 为 UserControl 具有正确的 ActualHeight ，但 UserControl 仅使用其中的一部分 - 80％左右。

我不确实是否修复 Stretch case（如何使 DataGrid 不会拉伸大于其行数？ ）或 Top case（如何使 UserControl 使用它可用的空间？）

解决方案

嗯，这是我最后的结果。大多数情况下，它从布局的角度来看我想要的。在我的DataContextChanged事件处理程序中：

<$>

p $ p> //每个网格
_reportObserver = new PropertyObserver< ItemCollection>（PrimaryGrid.Items）
.RegisterHandler（c => c.Count，c => UpdateMaxHeight（PrimaryGrid））;
UpdateMaxHeight（PrimaryGrid）;


PropertyObserver来自 http://joshsmithonwpf.wordpress.com/2009/07/11/one-way-to-avoid -messy-propertychanged-event-handling /

  //很多丑陋的硬编码
私人void UpdateMaxHeight（DataGrid grid）
 {
 double header_height = grid.ColumnHeaderHeight; 
 if（double.IsNaN（header_height））
 header_height = 22; 
 double margin_height = grid.Margin.Bottom + grid.Margin.Top; 
 grid.MaxHeight = header_height + margin_height + grid.Items.Count *（grid.RowHeight + 2）; 
 
 UpdateLayout（）; //这是运行时项目数量更改的关键点
} 
  

即使设置DataGrid的MaxHeight，事情还是很丑，所以我也必须设置RowDefinition的最大高度。但是这还是不正确的，导致margin_height加上。

 < RowDefinition Height =*MaxHeight ={ Binding ElementName = PrimaryGrid，Path = MaxHeight}/> 
  

在某些时候，我将考虑到我丑陋的最大高度代码中可选择的行详细信息。

对于Top vs Stretch来说，最终，由于ListView中用户控件的其他原因。一切大小现在很好

再次感谢我的问题。

The UserControl I'm trying to work with is essentially laid out like so:

<Grid>
   <Grid.RowDefinitions>
       <Row Height="*"/>
       <Row Height="*"/>
   </Grid.RowDefinitions>
   <wpftoolkit:DataGrid x:Name="PrimaryGrid"/> <!-- ~10 rows -->
   <Border>
      <Grid>
         <Grid.RowDefinitions>
             <Row Height="*"/>
             <Row Height="*"/>
         </Grid.RowDefinitions>
         <wpftoolkit:DataGrid x:Name="SecondaryGrid"/> <!-- ~2 rows -->
         <wpftoolkit:DataGrid x:Name="OtherGrid"/> <!-- ~50 rows -->
      </Grid>
   </Border>
</Grid>

This UserControl is then placed in my Window as the last member of a Grid, the only one with Height="*". I'm having problems with the way the DataGrids are sized.

If I set VerticalAlignment of the UserControl to Stretch in the Window, then PrimaryGrid gets 1/2 height of the UserControl, and each of the two inside the Border get 1/4. They are sized like this regardless of the number of rows each have, leaving OtherGrid with too little vertical space and the others with non-row whitespace inside the scrollview.

If I set VerticalAlignment to Top, the grids seem to size pretty well to their contents, except there is an inexplicable whitespace being left at the bottom of the UserControl. I used Snoop and the RowDefinition for the UserControl has the proper ActualHeight, but the UserControl only uses a portion of it - 80% or so.

I don't really mind whether I fix the Stretch case (How do I make the DataGrid not stretch larger than its number of rows?) or the Top case (How do I make the UserControl use all the space it has available to it?)

解决方案

Well, here's what I ended up with. It does what I want from a layout point of view, mostly. A bit more code behind than I'd like, but oh well.

In my DataContextChanged event handler:

//for each grid
_reportObserver = new PropertyObserver<ItemCollection>(PrimaryGrid.Items)
    .RegisterHandler(c => c.Count, c => UpdateMaxHeight(PrimaryGrid));
UpdateMaxHeight(PrimaryGrid);

PropertyObserver is from http://joshsmithonwpf.wordpress.com/2009/07/11/one-way-to-avoid-messy-propertychanged-event-handling/

//Lots of ugly hard-coding     
private void UpdateMaxHeight(DataGrid grid)
{
   double header_height = grid.ColumnHeaderHeight;
   if (double.IsNaN(header_height))
      header_height = 22;
   double margin_height = grid.Margin.Bottom + grid.Margin.Top;
   grid.MaxHeight = header_height + margin_height + grid.Items.Count * (grid.RowHeight+2);

   UpdateLayout(); //this is key for changes to number of items at runtime
}

Even after setting the DataGrid's MaxHeight, things were still ugly, so I had to set the max height on the RowDefinition's too. But that still wasn't right, causing the margin_height addition above.

<RowDefinition Height="*" MaxHeight="{Binding ElementName=PrimaryGrid, Path=MaxHeight}"/>

At some point, I'll take into account my optionally visible row details in my ugly max height code.

As far as Top vs Stretch, I ended up for other reasons having the usercontrol in a ListView. Everything sizes nicely now.

Thanks again for looking at my problem.

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